Hi,

There are both legal considerations as well as practical considerations with kitchen sink greywater.

Legally, some states consider kitchen sink water greywater and it can be used the same as other greywater sources. Logistically, it is greasier and contains more organic material, so is more prone to clogging filters and requires a design that won’t have clogging issues (like a branched drain system with large mulch basins).

If a state doesn’t consider it greywater, like in California, there is potential for a legal system, but it is much harder. Some people have had luck permitting a “vegetable wash station” and others were allowed an exemption (this requires a supportive permitting agency.)